For mild FAS, which drug class is generally used?

• A. Ketamine
• B. Alpha-2 agonists
• C. Opioids
• D. Local anesthetics

Answer: (B)

For mild fear- or anxiety-based handling, the sedative choice should calm the animal, reduce anxious tension, provide some analgesia, and be easily titratable and reversible. Alpha-2 agonists do exactly this. They act in the brain to decrease norepinephrine release, giving reliable sedation and anxiolysis with muscle relaxation and some analgesia. They’re dose-controllable and, importantly, reversible with an antagonist such as atipamezole, which is highly useful if the animal becomes too sedate or stressed.

Ketamine, while offering analgesia and dissociative anesthesia, can provoke unpredictable stimulation in anxious animals and may increase heart rate and blood pressure, making it less ideal for a mild anxiety state. Opioids provide analgesia but carry risks like respiratory depression and dysphoria, and they don’t specifically address anxiety or provide the level of controllable sedation desired for mild FAS. Local anesthetics can block pain but don’t produce systemic sedation or anxiolysis, so they don’t help with the animal’s fear or stress state.

So alpha-2 agonists are preferred because they address both calming and analgesic needs in a reversible, controllable way for mild anxiety during mild FAS.